An Innovative Bi₁₂ SiO₂₀ Multistage Cubic Nanospheres Cathode for High-Performance Bi//Zn Battery

Alkaline Bi//Zn batteries with superb safety, low cost, and high power density are promising candidates for large-scale electrical energy storage. However, their developments are severely limited by the Bi-based cathode as the unsatisfying capacity and cycle life. Herein, an innovative multistage cubic nanospheres Bi₁₂ SiO₂₀ (MCS-Bi₁₂ SiO₂₀ ) is successfully synthesized by a simple calcination method, which shows excellent energy storage performances of superior specific capacity (294 mAh g^-1 at 0.5 A g^-1 ) and outstanding rate capability (134 mAh g^-1 at 12 A g^-1 ). When coupled with Zn anode a superior MCS-Bi₁₂ SiO₂₀ //Zn is fabricated, which delivers a high energy density of 247.5 Wh kg^-1 at the power density of 375 W kg^-1 . Additionally, the MCS-Bi₁₂ SiO₂₀ //Zn battery shows excellent cycle life, which reserves more than 100 % of its original capacity after 5000 cycles. Such performance is higher than previously reported Bi//Zn battery and most other Zn batteries. This is the first example of using Bi₁₂ SiO₂₀ as cathode for RAZBs, which may provide highly promising material towards better Bi//Zn battery.